Implementation And Security Mechanism Research Of SIP Employed In MANET

Voice over IP(VoIP) System based on Session Initiation Protocol(SIP) has the advantage of low cost and high efficiency of bandwidth usage. It is meaningful to employ VoIP service in Mobile Ad hoc Networks(MANET). The core issue of this is to implement signaling protocol(such as SIP). Unfortunately, as the inherent features of MANET, such as acentric, self-organizing, distributing and infrastructure-less, it is unrealistic to directly implement SIP in such an environment. In the mean time, as the intrinsic characters of SIP and the poor security conditions in MANET, it is easy for attackers to impersonate the identity of legal users and tamper SIP messages exchanged, so as to mount various attacks. Consequently, the issue of SIP implementing and relating security considerations in MANET is an important matter to solve. This paper gives a thorough research of the issues described above.To realize the issue of SIP implementing in MANET, we have presented a novel SIP implementing mechanism based on signaling clusters for nodes in MANET, based on a kind of modularized software design framework, application-level clustering ideology and a kind of secure clustering algorithm. This mechanism includes two relating sub-mechanism: SIP registering mechanism(CS mechanism) and SIP session establishing mechanism(NSC mechanism). CS mechanism has overcome the registering flooding issue, which is a big problem brought by distributing registering mechanism(DS mechanism) in MANET. Meanwhile, CS mechanism has degraded network registering overhead and network establishing delay in the process of SIP Registering. In addition, node-to-node sessions initiating and establishing in MANET have been realized in NSC.To cope with the SIP security issues in MANET, we have presented a kind of security SIP registering scheme(HSR Scheme) and security SIP sessions establishing scheme(ESSE Scheme), which employed in our presented CS mechanism and NSC mechanism. The HSR scheme enables identity authentication between nodes and integrity protection of registering message transmitted in the process of SIP registering, based on HOTP(HMAC-based One Time Password) algorithm in OTPA(One Time Password Authentication); The ESSE scheme enables identity authentication between nodes, confidentiality and integrity protection of signaling message transmitted in the process of SIP sessions establishing,based on our improved IBSC scheme E-IBSC. Additionally, ESSE scheme has also realized the session key negotiation between nodes in the same process, which is used for encryption of media steams in the following phrase.